张量积型Said-Ball曲面的预处理渐近迭代逼近法

为加快张量积型Said-Ball曲面渐近迭代逼近法的收敛速度,探讨了张量积型Said-Ball曲面渐近迭代逼近法的预处理技术。首先利用对角补偿约化技术构造了预处理子,然后结合矩阵Kronecker积性质,采取预处理渐近迭代逼近法求解张量积型Said-Ball曲面。为进一步降低计算量并提高算法的稳定性,利用广义极小残差法求解预处理方程,得到预处理渐近迭代逼近法的非精确求解方法。分析了预处理渐近迭代逼近法及非精确求解方法的收敛性。最后用数值实例说明预处理子能大大减小迭代矩阵的谱半径,令预处理技术及其非精确求解方法的计算效率明显提高。此外,由于对角补偿预处理子能改善配置矩阵的谱分布,因此也可用于对广义极小残差法的预处理,以改善其收敛性。     

叠加压缩相干态的量子统计性质

研究了叠加压缩相干态的量子统计性质,给出了压缩和反聚束效应与叠加系数之间的关系。结果表明,叠加压缩相干态具有压缩和反聚束的现象。压缩奇偶相干态的有关结果均作为特例包含在本文的一般结论之中。     

两纠缠原子之一与腔场相互作用过程的纠缠研究

使一对纠缠的二能级原子之一与单模真空腔场发生共振相互作用,通过选择不同的演化时间,对这个三体系统的其中之一做选择性测量,可调节另外两体的纠缠状态。在不做测量时,研究了在不同的初始状态下,三体纠缠及三体中两两纠缠的演化特性。结果表明,该体系纠缠都呈现周期性的振荡,特别是,通过选择合适的初始状态和演化时间可生成强壮纠缠态———W纠缠态;在特定演化时刻,可使两纠缠原子的纠缠信息完全转化到腔外原子和腔场中去。     

Dynamic Properties of Two-Dimensional Polydisperse Granular Gases

We propose a two-dimensional model of polydisperse granular mixtures with a power-law size distribution in the presence of stochastic driving. A fractal dimension D is introduced as a measurement of the inhomogeneity of the size distribution of particles. We define the global and partial granular temperatures of the multi-component mixture. By direct simulation Monte Carlo, we investigate how the inhomogeneity of the size distribution influences the dynamic properties of the mixture, focusing on the granular temperature, dissipated energy, velocity distribution, spatial clusterization, and collision time. We get the following results: a single granular temperature does not characterize a multi-component mixture and each species attains its own "granular temperature"; The velocity deviation from Gaussian distribution becomes more and more pronounced and the partial density of the assembly is more inhomogeneous with the increasing value of the fractal dimension D; The global granular temperature decreases and average dissipated energy per particle increases as the value of D augments.     

Small World Effects in a Harmonious Unifying Hybrid Preferential Model Networks

Small world effects in the harmonious unifying hybrid preferential model (HUHPM) networks are studied both numerically and analytically. The idea and method of the HUHPM is applied to three typical examples of unweighted BA model, weighted BBV model, and the TDE model, so-called HUHPM-BA, HUHPM-BBV and HUHPM-TDE networks. Comparing the HUHPM with current typical models above, it is found that the HUHPM networks has the smallest average path length and the biggest average clustering coefficient. The results demonstrate that the HUHPM is more suitable not only for the un-weighted models but also for the weighted models.     

Modified Wave Particle Duality and Black Hole Physics

de Broglie relation is revisited, in consideration of a generalization of canonical commuting relation. The possible effects on particle's localization and black hole physics are also discussed, in a heuristic manner.     

圆柱类构件超声相控阵聚焦模型

在利用平面相控阵超声换能器对圆柱类构件检测时,受曲界面结构引起的入射波和回波时延的影响,扫描声束的波阵面产生弯曲,在利用传统迭代遍历算法计算延迟时间时效率低,无法发挥相控阵换能器检测优势。针对上述问题,建立了一种基于圆柱类构件特征和耦合介质特性的超声相控阵扫描成像的聚焦模型。该模型基于换能器、耦合介质、圆柱类构件材料特性和几何关系以及声线模型和折射定律,建立了耦合介质及被检构件的声速、曲面曲率半径、阵列与曲面间的距离等关联的延迟时间聚焦控制模型。利用该模型计算出的延时时间,对各阵元发射时间进行控制,从而实现扫描声束的聚焦。该文以液体和有机玻璃制介质楔块为例,对圆柱钢曲面的相控阵声束聚焦进行了仿真实验,结果表明该文方法计算效率显著提升,同时声束可以在预设位置实现聚焦,验证了该模型在计算效率上的优势与有效性。     

影响石英单模光纤数值孔径测量的因素及分析

本文采用远场光斑法和光强法测量了石英单模光纤的数值孔径.实验结果表明,由光纤耦合条件不同导致的光斑形状变化,对数值孔径的测量影响不大,单模光纤的纤芯直径小,导致出射光存在较强的衍射现象,对数值孔径的测量造成较大的影响,无论采用光斑法还是光强法,需以衍射第1次极大为计算标准,尽量选择光斑中心为亮斑时测量其数值孔径.此外,...     

Syntheses,Structures and Photocatalytic Degradation Properties of Two Copper(Ⅱ)Coordination Polymers with Flexible Bis(imidazole)Ligand

Two copper(Ⅱ)coordination polymers{[Cu(bib)(nip)]·1.5H2O}n(1)and[Cu2(bib)(glu)2]n(2)(bib= 1,4-bis(2-methyl-imidazol-1-yl)butane,H2nip = 5-nitroisophthalic acid,...     

高频感应等离子体流动模型与微型电推进器流场特性分析

微型射频离子推力器具有结构简单、 工作寿命长、 推力动态范围大、 性能调节响应灵敏等特点,是国际微电推进领域的研究热点之一.射频离子推力器电离室内的感性耦合放电等离子体特性和推力器的性能密切相关.为此,文章建立了低气压、小尺寸微型射频离子推力器电离室内感性耦合等离子体流体模型,开展了电磁场、流场、化学反应浓度场的多物理...